Cervical Medical Device, System and Method

ABSTRACT

A device and method for dilating a cervical canal. The device includes an elongated member with an expandable anchoring component attached to its distal tip. An expandable dilating member is attached to the elongated member proximally of the anchoring component for dilating the cervical canal. The anchoring component can be expanded after insertion of the device into the cervical canal to correctly position the device relative to the canal. A device and method for sealing a cervical canal is also provided. The device includes a tube having an expandable seal assembly attached to its distal end. The seal assembly has a ridged or corrugated surface when it is in an expanded condition to provide a seal for the cervical canal.

This application is a continuation of U.S. App. 10/719,500 filed Nov.21, 2003, now U.S. Pat. No. 7,105,007, which claims priority to U.S.Provisional App. 60/428,397, filed on Nov. 21, 2002.

FIELD OF THE INVENTIONS

The present invention relates to medical devices, systems, and methodsfor dilating a cervical canal in a female patient.

BACKGROUND OF THE INVENTIONS

The cervix is a dense yet distendible organ that responds to internalpressure (within the endocervical canal) by expanding within anatomicallimits to assume the diameter or shape of the item causing the pressure.If this pressure is applied gradually, the tissues of the cervix willusually experience minimal damage. It has been observed that if thepressure is maintained for a short period of time, the cervix willtemporarily fix itself to that diameter. In other words, the cervix willtemporarily stay open even after the pressure has been removed. It willthen gradually return to its normal resting diameter of about 3-4 mm.

Since the early 1800s physicians have been attempting to visualize theendometrial cavity through the endocervical canal using a variety ofoptical instruments. In the late 1800s, Pantaleoni removed a uterinepolyp and used silver nitrate to control the bleeding, therebycompleting the first successful procedure done through a hysteroscope.

Hysteroscopy, both diagnostic and operative, has come a long way sincethen, but the fundamental challenges of hysteroscopy have remainedunchanged. The two most basic challenges of hysteroscopy are: (1)dilating or opening the cervix in order to permit the insertion of theinstrument of choice; and (2) distending the uterine cavity with someform of gas or liquid in order to see and operate.

The first challenge has been addressed in two ways. The first is aseries of mechanical dilators that are, for the most part, blunt tipped,tapered metal or plastic rods that are offered in a graduated set ofincreasing diameters. The mechanical dilators are gently inserted intothe cervix starting with the smallest and moving through the largersizes until the cervix is opened to the desired diameter. Unfortunately,this method can be painful for the patient and often results in tearingof the cervical tissues, which causes bleeding and frequently leads tounintentional perforation of the uterine wall.

Gynecologists recognized the benefits of a more gradual dilation of thecervix and two additional methods were pursued. The first is a seaweedbased product called Laminaria and the second is a prostaglandin baseddrug called Misoprostol also known as Cytotec®, which is manufactured byPfizer, Inc.

Laminaria is a very thin piece of seaweed that is inserted into theendocervical canal. As the Laminaria absorbs tissue fluid from the body,it swells gradually and dilates the cervix in the process. This methodhas the benefit of eliminating the pain associated with mechanicaldilation and allows the operator to avoid or use minimal mechanicaldilation. The problems associated with Laminaria are that it requires anadditional visit to the doctor because the medical procedure to beperformed must be done between 12 and 24 hours after the insertion ofthe Laminaria and there is no control of the final dilated diameter ofthe cervix.

Misoprostol is a drug that has a softening effect of the cervicaltissues, allowing cervical dilation with less force. It can beadministered either orally or through the vagina. In either case, thepatient can administer the drug herself but it does require a trip tothe pharmacy. There are however inconveniences associated with the useof Misoprostol. In the case of self-administration, it requires thecompliance of the patient and a prescription, and the patient must pickup the prescription from the pharmacy. Since it is a form ofprostaglandin, it may also contribute to uterine cramping, which causespain and discomfort. If the cervix become too soft, establishing a sealon the hysteroscope on the day of the procedure may be problematic. Likeall drugs, there can be numerous side effects and complicationsassociated with the use of Misoprostol.

The second and simultaneous effort to address the first challenge ofhysteroscopy is to make the instruments smaller, thus requiring asmaller opening of the cervix. This solution does indeed reduce thedifficulties and complications mentioned above, but at the cost of areduction in visual clarity. Additionally, the small instruments thatare required for these smaller hysteroscopes are inadequate for all butthe most basic procedures a gynecologist performs. These smaller scopesare thus restricted to limited visual diagnostic procedures only.

Since the uterus is only a potential cavity, it needs to be distended inorder to see into it, which is the reason for the second basichysteroscopic challenge. The two primary methods of distension have beenand remain to this day to pump gas (usually carbon dioxide) and a fluidof some kind into the uterus. There have been many fluids used foruterine distension over the years, such as physiologic saline, 5%dextrose in water, glycine, sorbitol and others. Each of these solutionsand gases carry certain benefits and complications.

All of these distension media do provide at least one common challengeto the hysteroscopist: the need to contain them within the confines ofthe uterine cavity such that a slight positive intrauterine pressure isestablished. It is this containment and resultant positive pressure thatdistends the walls of the uterine cavity, permitting visualization andprocedural manipulation by the physician. Typically, the distensionmedia escape past the hysteroscope down the endocervical canal and intothe vagina. This loss of fluid not only makes establishing andmaintaining a positive pressure difficult, it also allows for a fairlysignificant volume of contaminated fluid to flow onto the operating roomfloor. The flow of fluid onto the operation room floor represents asafety hazard for the operating room personnel and if the fluid beingused is a non-electrolyte, it also poses a safety risk to the patient.In the latter case, if enough non-electrolytic fluid is absorbed by thepatient, it can cause a condition known as hyponatremia, which has amorbidity and mortality risk associated with it. In order to avoid fluidoverload, the operating room personnel must carefully monitor how muchfluid is introduced into the patient versus how much is recovered, withthe net difference assumed to have been absorbed. If fluid is lost tothe drapes, floor, etc. this task becomes more difficult and lessaccurate.

SUMMARY

According to one aspect of the present invention, a cervical medicaldevice is provided. The device has an elongated member sized to beinserted into an undilated cervical canal. An expandable mechanism isattached to the elongated member. The device also has an anchoringfeature to anchor the device within the cervical canal.

According to another aspect, a cervical anchoring method is provided. Ahollow tube is inserted into a cervical canal. At least one expandabledilator is also inserted into the cervical canal. The at least oneexpandable dilator is then radially expanded within the canal to dilatethe cervical canal while the tube is in the canal.

According to another aspect, a cervical dilating device is provided. Thedilating device has an elongated member having a proximal end and adistal end. A first expandable component is attached to the distal endof the elongated member. A second expandable component is attached tothe elongated member proximally of the first expandable component. In anillustrated embodiment, the device also has a lumen running through theentire length of the device. An expansion mechanism is preferablycoupled to the first and second expandable components to expand theexpandable components.

According to another aspect, a cervical sealing device is provided. Thecervical sealing device has an elongated member having a proximal endand a distal end. An expandable seal assembly is attached to the distalend of the elongated member. The seal assembly has an uneven surfacewhen it is in an expanded condition.

According to yet another aspect of the invention, a method of dilating acervical canal is provided. A dilating device is inserted into thecervical canal. The dilating device includes an elongated member havinga first expandable component attached to the distal end of the elongatedmember. A second expandable component is attached to the elongatedmember proximally of the first expandable component. The firstexpandable component is expanded after the device is inserted into thecervical canal. The device is then retracted until resistance is feltand the second expandable component is expanded to dilate the cervicalcanal.

According to another aspect, a method of sealing a cervical canal isprovided. A sealing device is introduced into the cervical canal. Thedevice includes a tube and an expandable seal assembly attached to adistal end of the tube. The seal assembly has an even surface when it isexpanded. The seal assembly is expanded after the device is introducedinto the canal. The device may comprise an expansion mechanism coupledto the seal assembly.

According to yet another aspect, a method of providing a seal for acervical canal is provided. A cervical sealing device is inserted intothe cervical canal. The device includes a cannula having a plurality ofvalves. An inflatable balloon is attached to a distal end of thecannula, wherein the balloon has an uneven surface when inflated. Theballoon is then inflated after the device is inserted into the cervicalcanal to seal the canal.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will be readily apparent to theskilled artisan in view of the description below, the appended claims,and from the drawings, which are intended to illustrate and not to limitthe invention, and wherein:

FIGS. 1A-1C show various schematic views of an embodiment having adistal anchor and a dilating member;

FIG. 1D is a perspective view of an embodiment of the device;

FIGS. 2A-2F show a method of dilating a cervical canal;

FIGS. 3A-3B show two schematic views of another embodiment having a sealassembly over an intrauterine treatment device;

FIG. 4 is a view of an embodiment used to dilate and seal the cervicalcanal; and

FIGS. 5A-5D show perspective views of an alternative embodiment.

DETAILED DESCRIPTION OF THE INVENTIONS

The following detailed description of the preferred embodiments presentsa description of certain specific embodiments to assist in understandingthe claims. However, one may practice the present invention in amultitude of different embodiments as defined and covered by the claims.

Referring more specifically to the drawings for illustrative purposes,the present invention is embodied in the devices generally shown in theFigures. It will be appreciated that the devices may vary as toconfiguration and as to details of the parts, and that the methods mayvary as to the specific steps and sequence, without departing from thebasic concepts as disclosed herein.

One embodiment of the invention is illustrated by reference to FIGS.1A-1D. As shown in FIGS. 1A-1C, the device 1 has an elongated member 10having a proximal end and a distal end. Preferably, the elongated member10 is a slender, rod-like instrument. The elongated member 10 preferablyis about 15-30 cm long and has a diameter no greater than about 3 mm. Ina preferred embodiment, the elongated member 10 has a central lumen 50running along the length of the device 1. The skilled artisan willappreciate that, in some embodiments, the elongated member 10 may have alength substantially corresponding to the length of the cervical canal.

With reference to FIG. 1A, a distal anchor 20 is positioned along thedistal end portion of the elongated member 10, at or adjacent to thedistal tip of the elongated member 10. A dilating member 30 is alsopositioned along the distal end portion of the elongated member 10proximally of the distal anchor 20, as shown in FIGS. 1A-1D.

The distal anchor 20 preferably is an expandable member. According toone embodiment, the distal anchor 20 comprises an expandable member thatis adjustable between radially collapsed and radially expandedconditions. As shown in FIG. 1A, the distal anchor 20 is in a radiallyexpanded condition. In the radially collapsed condition, the expandablemember may be delivered to the anchoring location of the cervical canal,as will be more fully described below with reference to FIGS. 2A-2F.Once the distal anchor 20 is positioned at the anchoring location, thedistal member 20 may be expanded to the radially expanded condition. Thedistal anchor 20 in the radially expanded condition preferably has anexpanded outer diameter that is greater than the initial inner diameterof the cervical canal at the anchoring location such that the expandabledistal anchor 20 is adapted to radially engage the wall of the cervicalcanal at the juncture of the cervical canal and the endometrial cavityto anchor thereto. With the distal anchor 20 anchored at the anchoringlocation, the dilating member 30 may be expanded within the cervicalcanal to dilate the cervical canal from an initial inner diameter to adilated inner diameter that is greater than the initial inner diameterof the cervical canal.

In a preferred embodiment, the distal anchor 20 is a rounded balloon, asshown in FIG. 1D. Preferably, the distal anchor 20 has a diameter nogreater than about 5 mm. The distal anchor 20 may be expanded, orinflated, after it is inserted into the endometrial cavity. The device 1may then be gently pulled back until resistance is felt, establishingthat the tip of the device 1 is very close to the internal cervical os.This action is similar to inserting a Foley balloon catheter into theurinary bladder. According to an alternative embodiment of the device 1,the skilled artisan will appreciate that the distal anchor 20 is a smalldeployable umbrella-like device that can be used to determinepositioning of the device 1 relative to the internal cervical os in asimilar fashion to the method described above.

According to another embodiment, the device 1 has an optical imagingcomponent instead of the distal anchor 20. The optical imaging componentmay be, for example, an imaging fiber. The optical imaging componentresides in the central lumen 50 of the elongated member 10 and allowsthe operator to visually confirm the position of the distal tip of thedevice 1 before expanding the dilating member 30. Those skilled in theart will appreciate that the optical imaging component may be providedin addition to the distal anchor 20 as well.

According to an embodiment, the dilating member 30 comprises anexpandable member that is also adjustable between a radially collapsedcondition and a radially expanded condition. Preferably, the expandabledilating member 30 in the expanded condition has a working lengthsubstantially corresponding to the length of the cervical canal, and hasan expanded outer diameter that is greater than the initial innerdiameter of the cervical canal. The dilating member 30 may be insertedinto the cervical canal proximally adjacent to the anchoring location soas to substantially engage and dilate the cervical canal wall to thedesired dilated inner diameter.

In a preferred embodiment, the dilating member 30 is an inflatableballoon that can be used as a dilator for the cervical canal wall, asshown in FIGS. 1A-1C. More preferably, the balloon is cylindrical, asshown in FIGS. 1A-1D. The dilating member 30 shown in FIGS. 1A-1D is inits inflated condition. The length of the balloon 30 in its inflatedcondition is preferably between 40 mm and 100 mm, and more preferablyabout 60 mm. The overall diameter of the balloon 30 in its inflatedcondition is preferably between 5 mm and 20 mm, and more preferablyabout 8 mm.

The overall diameter of the deflated balloon 30 is preferably less than3.5 mm, and more preferably less than about 3 mm because theendocervical canal has a normal resting diameter of about 3-4 mm. If thedilating member 30 is preferably less than 3 mm in diameter in itscollapsed position, there will be less force for the initial insertioninto the cervical canal, which will provide more control for theoperator and a reduction in tearing of cervical tissue and inadvertentperforations of the uterine wall.

The balloon 30 may be attached to the distal end portion of theelongated member 10. The balloon 30 may be inserted into theendocervical canal and is then inflated in order to dilate the canal toa predetermined diameter. A skilled artisan will appreciate that inanother embodiment, the device 1 does not have a distal anchor 20 andmay be used to dilate the cervical canal with only the dilating member30 attached to the elongated member 10.

FIGS. 2A-2F show a method of using an embodiment of the device 1 todilate the cervical canal. The embodiment shown in FIGS. 2A-2F has botha distal anchor 20 and a dilating member 30. As shown in FIG. 2A, thedevice 1 is inserted into the endocervical canal 70. FIG. 2B shows thedistal anchor 20 being inflated, preferably with a fluid-filled syringe,in the endometrial cavity 80. As shown in FIG. 2C, the device 1 may thenbe retracted until the resistance of the distal anchor 20 against theinternal cervical os 90 is felt. In this position, the device 1 isproperly positioned in the canal in its anchoring location.

Once the device 1 is in the anchoring location, the dilating member 30may be expanded preferably with gradually increasing pressure from afluid filled syringe until the maximum volume of the dilating member 30is reached, as shown in FIG. 2D. The skilled artisan will appreciatethat the distal anchor 20 and the dilating member may be inflated byother methods as well.

In a preferred embodiment, the expandable members of the distal anchor20 and dilating member 30 are independently inflatable. Those skilled inthe art will understand that there is a choice of inflation mechanismsfor the distal anchor 20 and the dilating member 30. According to oneembodiment, the operator may manually inflate the distal anchor 20and/or the dilating member 30 with a syringe or a syringe-like device.In certain embodiments, the syringe may be filled with liquid. Otherexpandable materials, including but not limited to gases and expandablefoams and plastics, may be used to inflate the distal anchor 20 and thedilating member 30 as well. A skilled artisan will appreciate that thedistal anchor 20 and dilating member 30 may also be expanded by means ofmechanical or chemical expansion.

According to yet another embodiment, the device 1 further includes anautomated expansion system that is coupled to the expandable dilatingmember 30. The automated expansion system gradually expands the dilatingmember 30 to the expanded condition over a longer period of time, suchthat tissue trauma and pain of the dilation is reduced. In yet anotherembodiment, the automated expansion system comprises a monitoringassembly and a control assembly. The monitoring assembly monitors thevalue of a predetermined parameter related to the expansion of thedilating member 30, and the control assembly controls expansion of thedilating member 30 according to the monitored value. In one embodiment,the control assembly can stop expansion of the dilating member 30 uponthe value or the parameter meeting a predetermined set point. Accordingto another embodiment, the set point is not predetermined but rathercalculated based on one or more other monitored or otherwise observedparameters related to the patient (e.g., initial inner diameter of thecervical canal or other anatomical considerations). In yet anotherembodiment, the gradual expansion of the dilating member 30 iscontrolled at a set rate (e.g., volume/unit time) until either apredetermined or calculated value, such as volume, diameter, or time, ismet. In still another embodiment, the gradual expansion of the dilatingmember 30 is controlled to terminate at a constant end diameter valuebased on a measured resistance at the cervical canal wall to expansion(i.e., pressure required to change). Specified parameters may includeactual values, such as pressure, volume, time, diameter, etc., or ratesof change thereof, or combinations of any of the foregoing. According toyet another embodiment, the expansion of the expandable dilating member30 is controlled manually by a healthcare provider.

The dilating member 30 may be allowed to remain at its full volume for atime period to dilate the cervical canal. As shown in FIG. 2E, both thedistal anchor 20 and the dilating member 30 may then be deflated toremove the device 1 from the cervical canal. At this point, the cervicalcanal remains dilated, as shown in FIG. 2F, and a hysteroscopic or otherintrauterine device can then be inserted into the uterus before thecervix relaxes down to its natural resting diameter.

Another embodiment provides for a collapsed, mesh-like guide tube thatmay be introduced on a flexible introducer into the endocervical canal.Introducer may then removed from the endocervical canal and the meshguide tube remains in place in the canal. The mesh guide tube ispreferably formed from a synthetic plastic material and about 3-3.5 mmin diameter. A dilating device, including but not limited to the device1, or a series of successively larger dilating devices where eachsubsequent dilating device has a larger diameter, may then be introducedinto the canal through the mesh guide tube to gradually dilate thecanal.

Those skilled in the art will appreciate that various expandablematerials may be used to form the balloons 20, 30 and other structuralcomponents of the device 1. Preferably, the balloons 20, 30 arerigid-walled balloons formed from polyethylene terephthalate (PET). Askilled artisan will appreciate that other materials, including but notlimited to nylon or silicon, may be used for the balloons 20, 30 aswell. The features shown in FIGS. 1A-1C may be modified with suitablesubstitutes, such as, for example, replacing inflatable balloons withother expandable members, such as expandable cages, expanding foam,expanding chemical materials and the like, as would be apparent to oneskilled in the art.

According to yet another embodiment, the elongated member 10 of thedevice 1 is not hollow and is used only for dilation purposes.Accordingly, the skilled artisan will understand that the device 1design may be simplified and profiles may be minimized to allowatraumatic passage of the device 1 into an undilated cervical canal andstill allow for the controlled dilation of the cervical canal.

The device 1 may be used as a stand-alone cervical canal dilator devicethat can be subsequently removed for later procedures to be performedwith other medical devices. In a preferred embodiment, the proximal endof the device 1 may also be positioned, or slid, over the distal endportion of another medical device 60 (such as a hysteroscopic orintrauterine device), as shown in FIG. 1A. The proximal end of theelongated member 10 is preferably coupled to the distal end portion of ahysteroscopic or intrauterine device 60 with ports adapted to couple toat least one inflation device to inflate each of the balloons 20, 30, asschematically shown by arrows 40 in FIG. 1A. In the case of coaxial useof the device 1 over another device through the lumen 50, a stop areamay be provided on the elongated member 10 to abut the tip of the otherdevice 60 for coupling the device 1 to the other device 60.

Accordingly, existing intrauterine treatment or diagnostic devices maybe modified by use of the embodiments of the present invention to allowfor dilation of and/or sealing of the cervical wall. The skilled artisanwill appreciate that the device 1 may be preloaded onto an internaltreatment device and inserted together. Dilation of the cervical canaland sealing against fluid leakage from the uterus may be achieved usingthe device 1.

The invention, according to another aspect, includes a medical devicesystem and method that may be positioned within a cervical canal, allowpassage of fluids into the uterus through the cervical canal, and alsoprovide a substantial seal against flow of pressurized fluids fromwithin the uterus and outward through the cervical canal. In someembodiments, the device is an integral component to varioushysteroscopic devices that require some form of fluid or gas containmentand control during hysteroscopic or intrauterine procedures.

The device includes a cervical sealing/anchoring expandable element,such as a balloon that is designed to work in conjunction withhysteroscopic or other intrauterine devices. When the balloon ispositioned over a hysteroscopic or intrauterine device and the device isinserted into the uterus, the balloon, or other expandable element, isinflated, or otherwise expanded, thereby creating a seal between thedevice and the wall of the endocervical canal, as will be more fullydescribed below. The expandable element may be either curved orstraight.

According to another aspect of the invention, the system includes atranscervical treatment device assembly with the device, which comprisesan elongated body having a proximal end portion and a distal endportion. The treatment assembly and seal assembly are disposed at leastin part along the distal end portion. The distal end portion is adaptedto be positioned at least in part within the cervical canal with theproximal end portion located externally of the body proximally of thevagina. The treatment assembly along the distal end portion isconfigured for use in performing a medical procedure within the femalereproductive system, such as within the uterus or fallopian tubes. Theseal assembly, also along the distal end portion, substantially sealsagainst flow of pressurized fluid from within the uterus and outwardfrom the body though the cervical canal.

FIGS. 3A and 3B illustrate an embodiment of the invention, whichprovides a cervical sealing device 100 that is adapted to seal acervical canal against leakage of pressurized fluid from the uterusduring use with an internal device delivering such fluids into theuterus. In one embodiment shown in FIGS. 3A and 3B, the device 100comprises an elongated body 200 having a proximal end portion, a distalend portion, and a lumen 500 extending through the entire length of thedevice 100.

The cervical sealing device 100 in the embodiment shown in FIGS. 3A and3B is configured to fit over an outer surface of another medical device,such as, for example, an interuterine fluid delivery device. Preferably,the lumen 500 is configured to fit around and engage an outer surfacealong the distal end portion of an intrauterine treatment device.

A distal stop region 600 is preferably provided at the distal tip of thedevice 100, as shown in FIG. 3B. The distal stop region 600 ispositioned at the distal tip of the lumen 500. The distal stop region600 allows precise placement of a seal assembly 300 relative to thelumen 500 and keeps the seal assembly 300 from sliding along the lumen500.

The seal assembly 300 is located along the distal end portion of theelongated body 200. The seal assembly 300 provides a seal against theoutward flow of pressurized fluids from within the uterus and externallyaround the cervical sealing device 100. The seal assembly of theillustrated embodiment, shown in FIGS. 3A and 3B, is a corrugatedinflatable balloon, which provides for regions of increased expansion,separated by regions of relatively decreased expansion when inflated. Inthis embodiment, the balloon is adjustable between a radially collapsedcondition for delivery into the cervical canal and a radially expandedcondition that radially engages the inner wall of the cervical canal toeffect the seal. In a preferred embodiment, the balloon 30 has 3-4ridges. The ridges of the balloon provide for a “keyway” effect along anengaged cervical canal wall, helping to secure or anchor the sealassembly 300 in place during pressurization of the distal uterus, andalso helps to prevent leakage of pressurized interuterine fluid. It willbe understood that the pressure points are anchoring features created bythe regions of increased expansion provide a seal for the cervicalcanal.

A skilled artisan will appreciate that other substitute seal members maybe used, such as, for example, a series of discrete balloons or otherexpandable structures, such as cages or the like. In a preferredembodiment, the seal assembly 300 comprises a plurality of expandablemembers located that are spaced in series along a length of the distalend portion of the elongated body 200 (see FIG. 4 and attendant text).In one embodiment, the aggregate length of the expandable memberscorresponds to a substantial portion of the length of the cervicalcanal. Such spaced expandable members provide a “keyway” effect along acervical wall with a series of dilated regions separated by regions lessdilated, or in some cases the areas of separation may not be dilated atall.

Preferably, the outer diameter of the device 100 along the region of theseal assembly 300 is increased by at least about 2 millimeters when theseal assembly 300 is activated or expanded to seal against fluid flowfrom the uterus. More preferably, the outer diameter of the device alongthe seal assembly 300 region is increased by between about 3 and about 4millimeters during the sealing mode of use.

The inflatable balloon or balloons 300 are preferably coupled to aninflation source, shown schematically by way of an arrow 400 in FIG. 3A.Those skilled in the art will understand that the inflation source maybe coupled to seal assembly 300 at any point and that various inflationsources, such as the ones described above, may be used to expand theseal assembly 300. The seal assembly preferably has a length between 40mm and 100 mm, and more preferably about 60 mm. In one embodiment, theseal assembly 300 engages the cervical wall along the entire effectivelength of the cervical wall.

It is important to note that the dilation of the cervix in response topressure actually causes a reduction in that pressure. Furthermore, theendocervical canal does not dilate uniformly. It only dilates wherepressure is applied. Thus, one can dilate one area of the endocervicalcanal without increasing the diameter of the rest of the canal.

Another embodiment will be described with reference to FIG. 4. The sealassembly 300 is preferably designed to create one or more pressurepoints 700. Preferably, these pressure 700 points are narrow, annularpressure points along the length of the cervical canal. Alternatively,the seal assembly may be dimpled to create the pressure points. In apreferred embodiment shown in FIG. 4, the seal assembly 300 is a balloonshaped such that when it is inflated, it assumes a shape that resemblesseveral, evenly spaced annular donuts or rings on a pole that runsthrough the donut holes, as shown in FIG. 4. The area where the donut orring contacts the wall of the cervical canal is a higher pressure point700, and the spaces between the donuts or rings are lower pressurepoints 800.

The illustrated seal assembly 300 works as a seal because it hasincreased surface contact with the endocervical canal and createsseveral distinct “dams” due to a slightly higher pressure in the area700 of the donut or ring relative to the adjacent low pressure bands800. These “dams” will prevent fluid or gas loss from the uterus throughthe cervical canal.

In addition to fluid and gas control, the cervical seal assembly 300 ofFIG. 4 also acts as an anchor because of the alternating areas of highand low pressure corresponding to the annular rings 700 and spaces 800along the length of the balloon 300. The cervix will dilate to the shapeof the balloon 300 when the balloon 300 is inflated in the endocervicalcanal, as shown in FIG. 4. The spaces of lower pressure 800 between therings create areas of the cervical canal that are not dilated as much asthe areas 700 corresponding to the annular rings. As these less-dilatedareas 800 have a smaller diameter than the balloon's rings, the sealassembly 300 cannot be moved without first dilating these narrower bandsof the cervical canal.

Since, in the preferred embodiment, there are several rings, thecoefficient of friction is quite high and an anchoring effect results.Thus, the seal assembly 300 also provides an increased coefficient offriction between the hysteroscopic device and the walls of theendocervical canal. This increase coefficient of friction stabilizes theposition of the device 100 relative to the endocervical canal, andfurther minimizes any inadvertent extraction of the device 100 or achange in position of the device 100 inwardly or outwardly that mightresult in an undesirable result. If the operator of the device 100 needsto reposition the device 100, the balloon 300 is preferably deflated toreposition the device 100 before the balloon 300 is reinflated (providedit is safe to do so). As with previously described embodiments, it willbe understood that the seal assembly of FIG. 4 can be a balloon, asillustrated, or other expandable element.

In an embodiment shown in FIGS. 5A-5D, the device 110 permitsindependent movement of a hysteroscopic or other intrauterine devicerelative to the device 110 itself. FIG. 5A is a perspective view of theassembled device 110 prior to insertion into the endocervical canal.FIG. 5B shows an exploded view of the device 110, which comprises anobturator 710 and a rigid-walled cannula 210, which is attached a sealassembly 300, which can be as described above on the distal end of thecannula 210.

The obturator 710 may be used to insert the cannula 210 into theendocervical canal. The cannula 210 can be either curved or straight andmay have an optical imaging component. The seal assembly 300 is attachedto the outer surface of the cannula 210. As shown in FIGS. 5A-5C, thecannula 210 also has a valve 410 for use with the illustrated inflatableseal assembly.

FIG. 5C is a perspective view of the device 110 with the seal assembly300 expanded after the obturator 710 has been removed. With reference toFIG. 5D, the cannula 210 has an arrangement of diaphragm-shaped seals610 on its proximal end, which act as a second valve in addition tovalve 410. While the seals 610 provide an additional seal, in additionto valve 410, for preventing leakage of fluid or gas through thecervical canal, the seals 610 do allow other devices, such ashysteroscopic or other intrauterine devices to pass through the device110 and into the endometrial cavity.

The inner diameter of the cannula 210 and its seals 610 preferablycorresponds to the outer diameter of a hysteroscopic or intrauterinedevice that is used with the device 110. The skilled artisan willappreciate that there is enough clearance between the inner diameter ofthe cannula 210 and the outer diameter of the hysteroscopic orintrauterine device so that the hysteroscopic or intrauterine device canmove easily through the device 110. The holes in the seals 610 areslightly smaller than the outer diameter of the hysteroscopic orintrauterine device so that a seal can be established between thedevices. Those skilled in the art will understand that this embodiment,when used in conjunction with a hysteroscopic or intrauterine device,functions similarly to a surgical trocar used with a laparoscopicinstrument.

It will be understood that the present invention improves the ability toperform medical interventional procedures to the female reproductivesystem via the cervical canal by providing for one or more of thefollowing benefits: anchoring interventional devices with precise,predictable position relative to the cervical canal os; dilating thecervical canal wall; and sealing the cervical canal against leakage ofpressurized fluids from the uterus.

Thus, a wide variety of existing procedures and related devices maybenefit by incorporation of or otherwise adjunctive use with the presentinvention. In one particular regard, hysteroscopy, endometrial ablation,and other intrauterine devices and related methods benefit from theability to dilate, seal, and/or anchor along the cervical canal in apredictable and reliable manner.

The present invention is highly beneficial and specially adapted for usewithin the cervical canal. However, it is understood that furthermodifications or improvements may be made to adapt the various featuresand embodiments for use in other regions of the body. For example, otherprocedures benefiting from the ability to anchor a treatment ordiagnostic device at a precise location along a lumen, in particularrelation to a luminal ostium, would benefit by adjunctive use with suchembodiments as herein described. In addition, where other needs exist tocontrollably dilate a lumen, applications of certain of the embodimentsand features for controlled dilation are contemplated. Still further,the ability afforded by certain aspects of the present invention toeffectively seal around a treatment device to prevent fluid flowtherearound may be useful in other procedures within other body lumensor spaces.

Those skilled in the art may practice the principles of the presentinvention in other specific forms without departing from its spirit oressential characteristics. Accordingly, the disclosed embodiments of theinvention are merely illustrative and do not serve to limit the scope ofthe invention set forth in the following claims.

1. A cervical canal dilator comprising: an elongate member having adistal end and a proximal end, said distal end adapted for insertioninto the endocervical canal of a patient; an expandable dilating memberdisposed on the distal end of the elongate member, said expandablemember being operable to selectively expand from a small diameter to alarge diameter; said expandable dilating member have a contoured outersurface adapted to engage the wall of the endocervical canal.
 2. Thecervical canal dilator of claim 1 wherein the elongate member is a tubehaving a lumen extending from the proximal end of the elongate member tothe distal end of the elongate member.
 3. The cervical canal dilator ofclaim 1 wherein the elongate member is a hysteroscope.
 4. The cervicalcanal dilator of claim 1 wherein the elongate member is a hysteroscopicsheath adapted for passage of a hysteroscope.
 5. The cervical canaldilator of claim 1 wherein the expandable dilating member is acorrugated balloon, having outwardly projecting corrugations.
 6. Thedevice of claim 1, wherein the expandable dilating member has an unevenouter surface when it is expanded.
 7. The cervical canal dilator ofclaim 1, wherein the expandable dilating member is a ridged balloon withoutwardly projecting ridges when inflated.
 8. The cervical canal dilatorof claim 1, wherein the expandable dilating member is a ridged balloonwith a series of spaced annular ridges along a length of the expandablemechanism.
 9. The cervical canal dilator of claim 1, wherein expandabledilating member is a ridged balloon sized and dimensioned to fitentirely within a cervical canal of a patient.
 10. The device of claim9, wherein the second expandable dilating member has a length between 40millimeters and 100 millimeters when expanded.
 11. The device of claim9, wherein the second expandable dilating member has a diameter between5 millimeters and 20 millimeters when expanded.
 12. A method ofaccessing the uterus of a female patient through the cervical canal,said method comprising: inserting a dilating device into the cervicalcanal, the dilating device comprising an elongate member having a lumenpassing the elongate member, an expandable dilating member attached to adistal end of the elongate member, said expandable dilating memberhaving means for engaging the wall of the cervical canal disposed on theouter surface thereof; expanding the expandable dilating member suchthat the means for engaging engages the wall of the cervix; inflatingthe uterus with fluid and maintaining the expandable dilating member inan expanded configuration; passing hysteroscopic instrumentstranscervically through the lumen of the elongate member whilemaintaining a substantially fluid tight seal between the wall of thecervical canal and the outer surface of the expandable dilating member.13. The method of claim 12, wherein the device further comprises anexpansion mechanism coupled to expandable dilating member.
 14. Themethod of claim 12, wherein the expandable dilating member is expandedusing a fluid-filled syringe coupled to the expandable dilating member.15. The method of claim 12, wherein the first and second expandablecomponents are expanded using a gas-filled syringe coupled to the firstand second expandable components.
 16. The method of claim 12, whereinthe expandable dilating member is rigid-walled balloon.